If you’re interested in cryonics, aim to preserve your brain structure at death

This is a follow-up post to my “if you’re interested in cryonics, become interested in longevity”. There was one good counter-argument that I wanted to mention there, but I realized is important to discuss in its own right.

It goes like this: “Sure, maximizing your longevity means you’re more likely to get better cryopreservation, but it also increases the chances your brain will decay to the point there will be nothing left of you to preserve at all.” Another way to put it is that cryonics rests on the premise that the structure of the brain is what is ultimately important in the case of future revival, even if the individual neurons die. But a preserved brain structure upon death is not guaranteed in today’s world.

In particular, this counter-argument can be broken down into two specific scenarios:

1.  The longer you live, the greater are your odds of dying due to dementia, in particular Alzheimer’s, which causes severe brain atrophy

Statistically, it is true that dementias are highly age-associated, and their typical age of onset is later than that of the other horsemen (cardiovascular disease, cancer, and diabetes). Their risk generally only becomes significant (20%+) past the age of 80.

Sadly, there is currently no cure for Alzheimer’s or other dementias, and their mechanisms remain poorly understood. What we do know is that they are highly heritable, with the heritability of Alzheimer’s estimated at about 70% from twin studies. The largest known component of that is your variant of a single gene called APOE, which you can test by ordering a $100 kit online.

Of course, knowing one’s risk of Alzheimer’s would be quite useless if you could do nothing about it. Luckily, there is emerging consensus that the following 4 interventions work: (1) exercise, both cardio and strength, (2) adequate sleep, (3) maintaining a healthy weight and glucose levels via diet, and (4) being cognitively engaged – e.g. learning new skills, reading, and just generally avoiding mental languor. Moreover, these interventions appear to work better if your genetic risk is higher.

Lastly, biomedical science is not static, and I would expect much progress to be made in tackling Alzheimer’s and other dementias in the next few decades. As I mentioned in the other post, widespread availability of prevention/treatment typically comes much later than experimental or off-label availability, so if your genetic risk is high you should also be paying more attention to new developments in this field and be willing to experiment.

2. The longer you live, the greater are your odds of dying following a protracted comatose phase during which your brain degenerates

This is something I only very recently learned about from listening to an interview with Nectome CEO Robert McIntyre (now Aurelia Song). She makes the claim, based on her experience examining post-mortem brains of hospice patients, that those patients who spent several days in a coma prior to death subsequently had severely atrophied brains. This could be due to toxic chemicals being released or not filtered out as organs are shutting down, or an inadequate oxygen supply due to agonal breathing. Importantly, the atrophy is not an immediate consequence of cell death (which is inevitable), but rather its protracted nature over several days.

Patients usually end up in such a state due to advanced cancer, cardiovascular disease, or end-stage organ failure, all of which are highly associated with age. However, I would argue that it’s only when coma kicks in that suggests serious brain damage has started to occur. And, as I understand it, under many jurisdictions it is not inevitable that you will be kept alive if you enter a comatose state – especially if it requires life support. I therefore strongly suggest that anyone who wants to be cryonically preserved research the laws of their jurisdiction to find if they can sign an advance healthcare directive or power of attorney that would prevent being artificially kept in such a state. Or, better yet, if you see yourself heading in that direction, look into going to a jurisdiction in which medical aid in dying is legal, and make all arrangements to be cryonically preserved at the end of that procedure.

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I know these answers are a bit depressing, but it’s the best I could come up with given the present-day situation – and it’s better to be realistic and do something rather than just ignore the issue. In any case, I would be happy to hear what you all think.